Every things are saying in the title, I just would like to know how can I delete the IT polycies on my BlackBerry 8310 ?
I heard somewhere that I must ask this to my Blackberry administrator, but I can't contact him.

You can forcibly remove the IT Policy from your device, but you'll probably also forcibly remove your employed status from your company in the process.
Plus, the IT Policy will just get pushed back to your device from the BES anyway.